U.S. patent application number 17/260497 was filed with the patent office on 2021-10-14 for discharge device and hair care device.
The applicant listed for this patent is Panasonic Intellectual Property Management Co., Ltd.. Invention is credited to Hiroyuki INOUE, Yohei ISHIGAMI, Aya ISHIHARA, Hayato KIKUCHl, Masato KINOSHITA, Yasunori MATSUI.
Application Number | 20210315349 17/260497 |
Document ID | / |
Family ID | 1000005693475 |
Filed Date | 2021-10-14 |
United States Patent
Application |
20210315349 |
Kind Code |
A1 |
INOUE; Hiroyuki ; et
al. |
October 14, 2021 |
DISCHARGE DEVICE AND HAIR CARE DEVICE
Abstract
A discharge device includes a discharge electrode, a counter
electrode that faces the discharge electrode in a first direction,
and voltage application unit that applies an application voltage
between the discharge electrode and the counter electrode. The
counter electrode includes a dome-shaped electrode having a
recessed inner surface recessed to a side opposite to the discharge
electrode in the first direction, and a protruding electrode that
protrudes in a second direction intersecting the first direction
from an opening edge of an opening of the dome-shaped electrode,
the opening being provided at an end opposite to the discharge
electrode. The discharge device forms a discharge path having at
least partial dielectric breakdown between the discharge electrode
and the protruding electrode, when the discharge occurs. The
discharge path includes a first dielectric breakdown region
generated around the discharge electrode and a second dielectric
breakdown region generated around the protruding electrode.
Inventors: |
INOUE; Hiroyuki; (Shiga,
JP) ; ISHIGAMI; Yohei; (Osaka, JP) ;
KINOSHITA; Masato; (Shiga, JP) ; ISHIHARA; Aya;
(Osaka, JP) ; MATSUI; Yasunori; (Shiga, JP)
; KIKUCHl; Hayato; (Shiga, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Panasonic Intellectual Property Management Co., Ltd. |
Osaka |
|
JP |
|
|
Family ID: |
1000005693475 |
Appl. No.: |
17/260497 |
Filed: |
February 4, 2019 |
PCT Filed: |
February 4, 2019 |
PCT NO: |
PCT/JP2019/003843 |
371 Date: |
January 14, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B05B 5/1691 20130101;
B05B 5/001 20130101; B05B 5/057 20130101; A45D 20/12 20130101; A45D
20/50 20130101; A45D 2200/202 20130101 |
International
Class: |
A45D 20/12 20060101
A45D020/12; A45D 20/50 20060101 A45D020/50; B05B 5/00 20060101
B05B005/00; B05B 5/16 20060101 B05B005/16; B05B 5/057 20060101
B05B005/057 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 29, 2018 |
JP |
2018-160761 |
Claims
1. A discharge device comprising: a discharge electrode; a counter
electrode that faces the discharge electrode in a first direction;
and a voltage application unit that applies an application voltage
between the discharge electrode and the counter electrode to
generate a discharge, wherein the counter electrode includes a
dome-shaped electrode having a recessed inner surface recessed to a
side opposite to the discharge electrode in the first direction,
and a protruding electrode that protrudes in a second direction
intersecting the first direction from an opening edge of an opening
of the dome-shaped electrode, the opening being provided at an end
opposite to the discharge electrode, the discharge device forms a
discharge path having at least partial dielectric breakdown between
the discharge electrode and the protruding electrode when the
discharge occurs, and the discharge path includes a first
dielectric breakdown region generated around the discharge
electrode, and a second dielectric breakdown region generated
around the protruding electrode.
2. The discharge device according to claim 1, wherein the counter
electrode includes a plurality of the protruding electrodes, the
plurality of the protruding electrodes being arranged at equal
intervals along a circumferential direction of the opening.
3. The discharge device according to claim 2, wherein the plurality
of the protruding electrodes is a pair of the protruding
electrodes.
4. The discharge device according to claim 1, wherein a shape of
each of the plurality of the protruding electrodes when viewed in
the first direction is a triangle.
5. The discharge device according to claim 4, wherein a vertex
angle of the triangle is 60 degrees or more.
6. The discharge device according to claim 4, wherein a base of the
triangle is longer than a perpendicular line from a vertex facing
the base to the base.
7. The discharge device according to claim 6, wherein a shape of
the opening when viewed in the first direction is circular, and a
length of the perpendicular line is less than or equal to a half of
a radius of the opening.
8. The discharge device according to claim 4, wherein the triangle
is an isosceles triangle.
9. The discharge device according to claim 1, wherein the first
dielectric breakdown region and the second dielectric breakdown
region are formed apart from each other in the discharge path.
10. The discharge device according to claim 1, wherein the each of
the plurality of the protruding electrodes is inclined in a
direction away from the discharge electrode in the first
direction.
11. The discharge device according to claim 1, wherein the each of
the plurality of the protruding electrodes has a curved surface on
a surface facing the discharge electrode at a tip.
12. The discharge device according to claim 1, wherein the
plurality of the protruding electrodes of the counter electrode is
arranged in a flow path of an airflow generated by an airflow
generator and at positions where the airflow flows at a same
velocity.
13. A hair care device comprising: the discharge device according
to claim 1; and an airflow generator that generates an airflow with
respect to the discharge device.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a discharge device and a
hair care device including the discharge device. In particular, the
present disclosure relates to a discharge device including a
discharge electrode and a counter electrode, and a hair care device
including the discharge device.
BACKGROUND ART
[0002] Conventionally, an electrostatic atomizer that produces
charged fine particle water is known (see, for example, PTL 1). The
electrostatic atomizer disclosed in PTL 1 includes a discharge
electrode having a tip and a counter electrode located to face the
tip. The electrostatic atomizer supplies water to the discharge
electrode and applies a voltage, thereby generating charged fine
particle water using the water supplied to the discharge electrode.
The charged fine particle water contains an active ingredient such
as a radical.
[0003] When the electrostatic atomizer (discharge device) disclosed
in PTL 1 is applied to, for example, a hair dryer, it is desired to
generate charged fine particle water containing large amounts of
acidic components such as nitrate ions and nitrogen oxides.
CITATION LIST
Patent Literature
[0004] PTL 1: Unexamined Japanese Patent Publication No.
2014-231047
SUMMARY OF THE INVENTION
[0005] The present disclosure provides a discharge device and a
hair care device capable of increasing a produced amount of acidic
components.
[0006] The discharge device according to one aspect of the present
disclosure includes a discharge electrode, a counter electrode, and
a voltage application unit. The counter electrode faces the
discharge electrode in a first direction. The voltage application
unit generates a discharge by applying an application voltage
between the discharge electrode and the counter electrode. The
counter electrode includes a dome-shaped electrode and a protruding
electrode. The dome-shaped electrode has a recessed inner surface
that is recessed to a side opposite to the discharge electrode in
the first direction. The protruding electrode protrudes in a second
direction intersecting the first direction from an opening edge of
an opening of the dome-shaped electrode, the opening being provided
at an end opposite to the discharge electrode. When a discharge
occurs, the discharge device forms a discharge path having at least
partial dielectric breakdown between the discharge electrode and
the protruding electrode. The discharge path includes a first
dielectric breakdown region and a second dielectric breakdown
region. The first dielectric breakdown region is generated around
the discharge electrode. The second dielectric breakdown region is
generated around the protruding electrode.
[0007] The hair care device according to one aspect of the present
disclosure includes the abovementioned discharge device and an
airflow generator that generates an airflow with respect to the
discharge device.
[0008] According to the present disclosure, it is possible to
achieve a discharge device and a hair care device capable of
increasing a produced amount of acidic components.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a sectional view of a discharge device according
to an exemplary embodiment.
[0010] FIG. 2A is a perspective view of a hair care device
according to the exemplary embodiment.
[0011] FIG. 2B is a perspective view showing a main part of the
hair care device.
[0012] FIG. 3 is a schematic circuit diagram of the discharge
device.
[0013] FIG. 4A is a plan view of a counter electrode used in the
discharge device.
[0014] FIG. 4B is a sectional view taken along line 4B-4B in FIG.
4A.
[0015] FIG. 5 is a plan view showing a main part of the counter
electrode used in the discharge device.
[0016] FIG. 6A is a conceptual diagram for describing a partial
breakdown discharge generated in the discharge device.
[0017] FIG. 6B is a conceptual diagram for describing a partial
breakdown discharge generated in the discharge device.
[0018] FIG. 7A is a graph showing a relationship among magnitude of
a discharge current flowing between the discharge electrode and the
counter electrode, presence or absence of a protruding electrode,
and a ratio of a produced amount of acidic components.
[0019] FIG. 7B is a graph showing a relationship among magnitude of
a discharge current flowing between the discharge electrode and the
counter electrode, presence or absence of a protruding electrode,
and a ratio of a generated amount of ozone.
[0020] FIG. 8 is a graph showing a relationship between presence or
absence of a protruding electrode and a ratio of a produced amount
of charged fine particle water.
[0021] FIG. 9 is a sectional view showing a main part of a
discharge device according to a first modification of the exemplary
embodiment.
[0022] FIG. 10A is a plan view of a counter electrode used in a
discharge device according to a second modification of the
exemplary embodiment.
[0023] FIG. 10B is a plan view of a counter electrode used in a
discharge device according to a third modification of the exemplary
embodiment.
[0024] FIG. 10C is a plan view of a counter electrode used in a
discharge device according to a fourth modification of the
exemplary embodiment.
[0025] FIG. 10D is a plan view of a counter electrode used in a
discharge device according to a fifth modification of the exemplary
embodiment.
[0026] FIG. 11 is a perspective view showing a main part of a hair
care device including the discharge device according to the second
modification of the exemplary embodiment.
DESCRIPTION OF EMBODIMENT
[0027] An exemplary embodiment and modifications described below
are merely examples of the present disclosure. The present
disclosure is not limited to the exemplary embodiment and
modifications, and besides the following exemplary embodiment and
modifications, various changes are possible depending on design or
the like without departing from the scope of the technical idea of
the present disclosure. Drawings used in the following exemplary
embodiment and modifications are schematic, and a dimensional ratio
or thickness ratio of components in the drawings may not reflect an
actual dimensional ratio.
Exemplary Embodiment
[0028] A discharge device and a hair care device according to the
present exemplary embodiment will be described below separately for
each item.
(1) Overview
[0029] An overview of discharge device 10 and hair care device 100
according to the present exemplary embodiment will now be described
with reference to FIGS. 1, 2A, and 2B.
[0030] In the following description, a lateral direction of
discharge device 10 is defined as an X-axis direction (or a second
direction), a front-rear direction is defined as a Y-axis direction
(or a first direction), and a vertical direction is defined as a
Z-axis direction. Further, the rightward direction of discharge
device 10 is defined as the positive direction of the X-axis, and
the leftward direction is defined as the negative direction of the
X-axis. Further, the forward direction of discharge device 10 is
defined as the positive direction of the Y-axis, and the rearward
direction is defined as the negative direction of the Y-axis.
Further, the upward direction of discharge device 10 is defined as
the positive direction of the Z-axis, and the downward direction is
defined as the negative direction of the Z-axis.
[0031] As shown in FIG. 1, discharge device 10 according to the
present exemplary embodiment includes discharge electrode 1,
counter electrode 2, voltage application unit 3 (see FIG. 3),
liquid supply unit 4 (see FIG. 3), and the like. Counter electrode
2 faces discharge electrode 1 in the first direction. In the
present exemplary embodiment, the first direction indicates the
front-rear direction (Y-axis direction). Voltage application unit 3
generates a discharge by applying an application voltage between
discharge electrode 1 and counter electrode 2. Liquid supply unit 4
has a function of supplying liquid 40 (see FIG. 6A) to discharge
electrode 1. Counter electrode 2 includes dome-shaped electrode 22,
protruding electrode 23, and the like.
[0032] In the present exemplary embodiment, counter electrode 2
includes, for example, a pair of protruding electrodes 23 as shown
in FIGS. 1 and 2B. That is, counter electrode 2 includes a
plurality of protruding electrodes 23, and the plurality of
protruding electrodes 23 includes at least a pair of protruding
electrodes 23.
[0033] As shown in FIG. 1, dome-shaped electrode 22 has recessed
inner surface 221 recessed to a side opposite to discharge
electrode 1 in the first direction. Protruding electrodes 23 are
provided so as to protrude in the second direction from opening
edge 222a (for example, see FIG. 4A) of opening 222 of dome-shaped
electrode 22 formed on an end opposite to discharge electrode 1.
Here, the second direction indicates a direction that intersects
the first direction, and in the present exemplary embodiment, it
indicates the lateral direction (X-axis direction).
[0034] Notably, it is sufficient that discharge device 10 includes,
as minimum components, discharge electrode 1, counter electrode 2,
and voltage application unit 3. Therefore, liquid supply unit 4 may
not be included in the components of discharge device 10.
[0035] Further, as shown in FIG. 2A, hair care device 100 according
to the present exemplary embodiment includes discharge device 10,
airflow generator 20, and the like. Airflow generator 20 generates
an airflow with respect to discharge device 10. In a case where
counter electrode 2 includes a plurality of protruding electrodes
23 as in the present exemplary embodiment, the plurality of
protruding electrodes 23 is preferably provided in flow path 300 of
an airflow generated by airflow generator 20 and at positions where
the airflow flows at the same velocity, as shown in FIG. 2B. Here,
the "positions where the airflow flows at the same velocity"
described in the present disclosure does not mean positions where
the airflow flows at exactly the same velocity. For example, the
"positions where the airflow flows at the same velocity" includes
positions where the airflow flows at different velocities that do
not affect the frequency of discharge in the plurality of
protruding electrodes 23.
[0036] Further, in discharge device 10, a voltage is applied by
voltage application unit 3 between discharge electrode 1 and
counter electrode 2, while, for example, liquid 40 is adhered to
and retained on the surface of discharge electrode 1. As a result,
a discharge is generated between discharge electrode 1 and counter
electrode 2, so that liquid 40 retained on discharge electrode 1 is
electrostatically atomized by the discharge. In other words,
discharge device 10 according to the present exemplary embodiment
constitutes a so-called electrostatic atomizer. Here, in the
present disclosure, liquid 40 retained on discharge electrode 1,
that is, liquid 40 to be electrostatically atomized, may be simply
referred to as "liquid 40".
[0037] As shown in FIG. 3, voltage application unit 3 applies an
application voltage between discharge electrode 1 and counter
electrode 2. Thus, a discharge is generated between discharge
electrode 1 and counter electrode 2. In particular, in the present
exemplary embodiment, voltage application unit 3 applies the
application voltage such that the magnitude of the application
voltage applied between discharge electrode 1 and counter electrode
2 varies periodically. Accordingly, a discharge is intermittently
generated between discharge electrode 1 and counter electrode 2. At
this time, mechanical vibration occurs in liquid 40 due to the
periodic variation of the application voltage. Here, the
"application voltage" described in the present disclosure means a
voltage applied between discharge electrode 1 and counter electrode
2 by voltage application unit 3 in order to generate a
discharge.
[0038] As will be described in detail later, due to application of
a voltage (application voltage) between discharge electrode 1 and
counter electrode 2, liquid 40 retained on discharge electrode 1 is
formed into a conical shape called a Taylor cone by receiving force
due to an electric field as shown in FIG. 6A. Therefore, the
electric field is concentrated on tip 40a (vertex) of the Taylor
cone. In this case, the sharper tip 40a of the Taylor cone, that
is, the smaller (the more acute) the vertex angle of the cone, the
smaller the electric field strength required for dielectric
breakdown. As a result, it becomes easy to generate a discharge
between discharge electrode 1 and counter electrode 2 with weak
electric field strength.
[0039] Further, liquid 40 retained on discharge electrode 1 is
alternately deformed into a first shape and a second shape by the
mechanical vibration. The first shape indicates the shape of the
Taylor cone shown in FIG. 6A. The second shape indicates a shape in
which tip 40a (vertex) of the Taylor cone is crushed (not shown).
As a result, the shape of the Taylor cone described above is
periodically formed. Therefore, a discharge is intermittently
generated between discharge electrode 1 and counter electrode 2 at
the timing at which the Taylor cone shown in FIG. 6A is formed.
[0040] Further, in discharge device 10, discharge electrode 1 and
protruding electrode 23 of counter electrode 2 are disposed to face
each other with a gap therebetween in the first direction (Y-axis
direction). Then, when the application voltage is applied between
discharge electrode 1 and protruding electrode 23 of counter
electrode 2 by voltage application unit 3, a discharge is
generated. At this time, when a discharge occurs, discharge path
200 (see FIG. 6A) is formed in which dielectric breakdown partially
occurs in at least a part of a region between discharge electrode 1
and protruding electrode 23. Formed discharge path 200 includes
first dielectric breakdown region 201 and second dielectric
breakdown region 202. First dielectric breakdown region 201 is
generated around discharge electrode 1. Second dielectric breakdown
region 202 is generated around protruding electrode 23. That is,
discharge path 200 in which dielectric breakdown occurs not
entirely but partially (locally) is formed between discharge
electrode 1 and protruding electrode 23 of counter electrode 2.
[0041] The "dielectric breakdown" described in the present
disclosure means that electrical insulation of an insulator
(including gas) separating conductors is broken, and the insulating
state cannot be maintained. Specifically, in a case of dielectric
breakdown of a gas, for example, ionized molecules are accelerated
by an electric field and collide with other gas molecules to be
ionized. Then, the ion concentration suddenly increases to cause a
gas discharge, so that dielectric breakdown occurs. That is, in
discharge device 10 according to the present exemplary embodiment,
when a discharge occurs, the gas (air) present in the path
connecting discharge electrode 1 and protruding electrodes 23 has
dielectric breakdown locally, that is, only in a part thereof.
Thus, discharge path 200 formed between discharge electrode 1 and
protruding electrode 23 does not reach entire dielectric breakdown,
but only has partial dielectric breakdown.
[0042] In this case, discharge path 200 includes first dielectric
breakdown region 201 generated around discharge electrode 1 and
second dielectric breakdown region 202 generated around protruding
electrode 23 of counter electrode 2 as described above. First
dielectric breakdown region 201 indicates a region where dielectric
breakdown occurs around discharge electrode 1, and second
dielectric breakdown region 202 indicates a region where dielectric
breakdown occurs around protruding electrode 23. Then, first
dielectric breakdown region 201 and second dielectric breakdown
region 202 are generated in distant regions of discharge path 200
so as not to come into contact with each other. In other words, in
discharge path 200, first dielectric breakdown region 201 and
second dielectric breakdown region 202 are separated from each
other. Therefore, discharge path 200 includes a region (insulation
region) where dielectric breakdown does not occur at least between
first dielectric breakdown region 201 and second dielectric
breakdown region 202. Thus, discharge path 200 between discharge
electrode 1 and protruding electrode 23 includes a region where
dielectric breakdown occurs partially while keeping an insulation
region in at least a part thereof. As a result, discharge path 200
is formed in a state where the electrical insulation is
lowered.
[0043] As described above, according to discharge device 10,
discharge path 200 in which dielectric breakdown occurs not
entirely but partially is formed between discharge electrode 1 and
protruding electrode 23 of counter electrode 2. With this
configuration, even when discharge path 200 in which partial
dielectric breakdown occurs, in other words, discharge path 200
including a region where dielectric breakdown does not occur in a
part thereof, is used, a current flows between discharge electrode
1 and protruding electrode 23 through discharge path 200, and thus,
a discharge occurs.
[0044] Note that the discharge in a mode in which discharge path
200 having partial dielectric breakdown is formed will be referred
to as "partial breakdown discharge" below. The partial breakdown
discharge will be described in detail in the section of "(2.4)
Partial breakdown discharge".
[0045] Here, the partial breakdown discharge generates a large
amount of energy as compared with a corona discharge. Therefore, in
the partial breakdown discharge, oxygen and nitrogen in the air
chemically react with each other to generate an acidic component
such as nitrogen oxide. When attached to, for example, skin, the
generated acidic component makes the skin mildly acidic. Therefore,
the acidic component accelerates, in the skin, the production of
moisturizing ingredients such as natural moisturizing molecules and
intercellular lipids. In other words, the acidic component has an
effect of boosting the ability of the skin to retain moisture. In
addition, the acidic component tightens cuticle that covers the
surface of the hair. That is, the acidic component also has an
effect of preventing discharge of water, nutrients, and the like
from inside of the hair.
[0046] In addition, when acidic components are generated by the
partial breakdown discharge, ozone is also generated
simultaneously. However, discharge device 10 according to the
present exemplary embodiment is configured such that an electric
field is concentrated on the tip of protruding electrode 23.
Therefore, a generated amount of ozone can be suppressed to the
same extent as that in the corona discharge.
[0047] Further, in the partial breakdown discharge, large amounts
of radicals about 2 to 10 times as much as that in the corona
discharge are generated. The generated radicals are the basis for
providing useful effects in various situations, besides
sterilization, deodorization, moisture retention, freshness
retention, and inactivation of viruses. Therefore, the generated
radicals can also be effectively utilized.
[0048] On the other hand, apart from the partial breakdown
discharge, there is a discharge in a mode in which a phenomenon
where dielectric breakdown (entire breakdown) occurs due to
development of a corona discharge is intermittently repeated. In
the following description, the discharge in such a mode will be
referred to as "entire breakdown discharge".
[0049] The entire breakdown discharge occurs by an operation
described below.
[0050] First, when a corona discharge develops, and dielectric
breakdown (entire breakdown) occurs, a relatively large discharge
current flows instantaneously. Immediately after a large discharge
current flows, the application voltage drops, and the discharge
current is cut off. When the discharge current is cut off, the
application voltage rises again, leading to dielectric breakdown.
That is, the abovementioned phenomenon is repeated in the entire
breakdown discharge. In this case, even in the entire breakdown
discharge, a large amount of energy is also generated as compared
with the corona discharge, as in the partial breakdown discharge.
Therefore, acidic components such as nitrogen oxides are generated
by the entire breakdown discharge. However, the energy generated by
the entire breakdown discharge is much larger than the energy
generated by the partial breakdown discharge. Thus, electrolytic
corrosion of the electrodes (discharge electrode 1, protruding
electrodes 23) due to the energy at the time of discharge becomes
larger than that in the partial breakdown discharge. Therefore,
considering the life of discharge device 10, it is preferable to
limit the discharge to the partial breakdown discharge.
[0051] That is, in discharge device 10 according to the present
exemplary embodiment, the partial breakdown discharge or the entire
breakdown discharge is caused between discharge electrode 1 and
protruding electrode 23 of counter electrode 2 that face each other
in the first direction with a gap therebetween. With this
configuration, the produced amount of acidic components can be
increased as compared with the case of the corona discharge.
Further, due to the electric field being concentrated on the tip of
protruding electrode 23, the generated amount of ozone can be
suppressed to the same extent as that in the corona discharge.
(2) Details
[0052] Hereinafter, discharge device 10 and hair care device 100
according to the present exemplary embodiment will be described in
detail with reference to FIGS. 1 to 5.
(2.1) Hair Care Device
[0053] Hereinafter, a hair dryer shown in FIG. 2A will be described
as an example of hair care device 100.
[0054] As shown in FIG. 2A, hair care device 100 includes discharge
device 10, airflow generator 20, and the like. Hair care device 100
further includes casing 101, grip 102, power cord 103, and the
like. Hair care device 100 may be a hair iron or the like.
[0055] Airflow generator 20 includes, for example, a small blower
fan. Airflow generator 20 generates an airflow blown out from an
opening of casing 101 using the outside air introduced by the
blower fan. As shown in FIG. 2B, hair care device 100 according to
the present exemplary embodiment is configured such that a part of
the airflow generated by airflow generator 20 passes through
counter electrode 2 of discharge device 10.
[0056] Casing 101 is made of a molded article formed using a
synthetic resin such as ABS, and is formed in a tubular shape
extending in the front-rear direction. Casing 101 is provided with
vent hole 104 formed in the front surface, vent hole 104
penetrating housing 101 in the front-rear direction (Y-axis
direction). Casing 101 houses inside discharge device 10, airflow
generator 20, and the like. As described above, discharge device 10
generates the active ingredients (acidic components, radicals,
charged fine particle water, etc.). The generated active
ingredients are discharged to the outside of casing 101 through
vent hole 104 by the airflow from airflow generator 20. Grip 102 is
connected to a lower end of casing 101.
[0057] Similar to casing 101, grip 102 is made of a molded article
formed using a synthetic resin such as ABS, and is formed in a
tubular shape extending in the vertical direction. Grip 102 is
connected to casing 101 so as to be movable (foldable) between a
first position and a second position. The first position indicates
a position in which the longitudinal direction of grip 102 is along
the vertical direction (a direction intersecting the longitudinal
direction of casing 101: the Z-axis direction) as shown in FIG. 2A.
The second position indicates a position where the longitudinal
direction of grip 102 is along the front-rear direction (a
direction substantially parallel to the longitudinal direction of
casing 101: the Y-axis direction).
[0058] As shown in FIG. 2A, hair care device 100 according to the
present exemplary embodiment is supplied with AC power from the
outside via power cord 103 extending downward from the lower end of
grip 102. Then, discharge device 10, airflow generator 20, and the
like of hair care device 100 are driven by the supplied AC
power.
(2.2) Discharge Device
[0059] As shown in FIGS. 1 and 3, discharge device 10 includes
discharge electrode 1, counter electrode 2, voltage application
unit 3, liquid supply unit 4, and the like. Discharge electrode 1,
counter electrode 2, voltage application unit 3, and liquid supply
unit 4 are held in electrically insulating housing 5 made of a
synthetic resin such as polycarbonate.
[0060] Discharge electrode 1 is composed of, for example, a
rod-shaped electrode. Discharge electrode 1 has tip 11 at one end
(upper end) in the longitudinal direction (vertical direction:
Y-axis direction), and base end 12 on the other end (an end
opposite to the tip, a lower end) in the longitudinal direction.
Discharge electrode 1 is a needle-shaped electrode in which at
least tip 11 has a tapered shape. Here, the "tapered shape" is not
limited to a shape having a sharp tip, but also includes a shape
having a rounded tip as shown in FIG. 1, etc. In the present
exemplary embodiment, tip 11 of discharge electrode 1 is formed in
a spherical shape having a diameter of, for example, 0.5 mm.
[0061] Counter electrode 2 is disposed at a position facing tip 11
of discharge electrode 1 in the first direction (front-rear
direction: Y-axis direction). Counter electrode 2 is made of, for
example, titanium. As shown in FIGS. 4A and 4B, counter electrode 2
includes a plate-shaped electrode body 21 that extends in the
lateral direction (X-axis direction). In counter electrode 2,
dome-shaped electrode 22 projecting forward (in the Y-axis
direction) is integrally formed in the center of electrode body 21.
That is, dome-shaped electrode 22 is formed in a flat hemispherical
shell shape in the front-rear direction by recessing a part of
electrode body 21 toward the front (Y-axis direction) by, for
example, a drawing die.
[0062] Further, as shown in FIG. 4B, dome-shaped electrode 22 has
inner surface 221 that is recessed forward (in the Y-axis
direction). In other words, dome-shaped electrode 22 has recessed
inner surface 221 recessed to a side opposite to discharge
electrode 1, which faces dome-shaped electrode 22, in the first
direction. As shown in FIG. 4B, inner surface 221 has inner
diameter D1 at first edge 221a (front edge) in the first direction
(front-rear direction) smaller than inner diameter D2 at second
edge 221b (rear edge).
[0063] Discharge electrode 1 and counter electrode 2 are disposed
such that, as shown in FIG. 1, central axis A1 of discharge
electrode 1 and central axis A2 of dome-shaped electrode 22 of
counter electrode 2 coincide with each other in a state where
discharge electrode 1 and counter electrode 2 are held in housing
5. Thus, discharge electrode 1 and counter electrode 2 are disposed
such that tip 11 of discharge electrode 1 and inner surface 221 of
dome-shaped electrode 22 of counter electrode 2 face each other in
the first direction (front-rear direction). Therefore, when the
application voltage is applied between discharge electrode 1 and
counter electrode 2, uniformity of the electric field at tip 11 of
discharge electrode 1 can be improved. As a result, when the
application voltage is applied from voltage application unit 3, it
is possible to reduce a variation in the shape of the Taylor cone
formed on tip 11 of discharge electrode 1.
[0064] Opening 222 is formed at the front end of dome-shaped
electrode 22 of counter electrode 2, that is, at the end opposite
to discharge electrode 1 that faces counter electrode 2. In the
present exemplary embodiment, opening 222 is formed in a circular
shape when viewed in the front-rear direction (first direction) as
shown in FIG. 4A.
[0065] Further, a plurality of (for example, two) protruding
electrodes 23 protruding from opening edge 222a (inner peripheral
edge) is integrally formed in opening 222. Specifically, each of
the plurality of protruding electrodes 23 is formed so as to
protrude in the lateral direction (second direction) from opening
edge 222a of opening 222. That is, each of the plurality of
protruding electrodes 23 is formed so as to protrude from opening
edge 222a of opening 222 toward the center of opening 222.
[0066] The plurality of protruding electrodes 23 is arranged, for
example, at equal intervals along the circumferential direction of
opening 222. The plurality of protruding electrodes 23 of the
present exemplary embodiment is a pair of protruding electrodes 23,
and the pair of protruding electrodes 23 is provided at positions
distant from each other by 180 degrees in the circumferential
direction of opening 222. In other words, the pair of protruding
electrodes 23 is provided at positions symmetrical about the center
of opening 222 as the point of symmetry (center of symmetry).
Opening 222 and the pair of protruding electrodes 23 are formed
(molded) by, for example, a punching die. The specific shape of
protruding electrode 23 will be described in the section of "(2.3)
Shape of protruding electrode".
[0067] Dome-shaped electrode 22 formed on electrode body 21 of
counter electrode 2 has a pair of caulking holes 211 penetrating in
the front-rear direction (Y-axis direction) on both the left and
right sides. Counter electrode 2 of the present exemplary
embodiment is subjected to heat caulking after a pair of caulking
projections 51 formed on housing 5 shown in FIG. 2B is inserted
into a pair of caulking holes 211. Thus, counter electrode 2 is
caulked and fixed to housing 5. Further, as shown in FIG. 4A,
electrode body 21 has grounding terminal piece 24 integrally formed
at the lower right corner.
[0068] As shown in FIG. 3, liquid supply unit 4 supplies liquid 40
for electrostatic atomization to discharge electrode 1. As an
example, liquid supply unit 4 is achieved using cooling device 41
that cools discharge electrode 1 to generate condensation water on
discharge electrode 1. Specifically, as shown in FIG. 1, cooling
device 41 includes, for example, a plurality of (four in the
example of FIG. 1) Peltier elements 411, radiator plate 412,
insulating plate 413, and the like. The plurality of Peltier
elements 411 is held by radiator plate 412. Each of the plurality
of Peltier elements 411 is arranged such that the upper side is a
heat-absorbing side and the lower side is a heat-dissipation side.
That is, the plurality of Peltier elements 411 is held by radiator
plate 412 on the heat-dissipation side. Cooling device 41 cools
discharge electrode 1 by applying a current to the plurality of
Peltier elements 411.
[0069] Further, the plurality of Peltier elements 411 is
mechanically connected to discharge electrode 1 via insulating
plate 413. That is, discharge electrode 1 is mechanically connected
to insulating plate 413 via base end 12. On the other hand, the
plurality of Peltier elements 411 is mechanically connected to
insulating plate 413 on the heat-absorbing side (upper side). Thus,
discharge electrode 1 and the plurality of Peltier elements 411 are
electrically insulated by insulating plate 413 and the like.
[0070] Cooling device 41 in the present exemplary embodiment cools
discharge electrode 1 mechanically connected to Peltier elements
411 on the heat-absorbing side by applying a current to the
plurality of Peltier elements 411. At this time, cooling device 41
cools entire discharge electrode 1 through base end 12 of discharge
electrode 1. Accordingly, the moisture in the air condenses and
adheres to the surface of discharge electrode 1 as condensation
water. That is, liquid supply unit 4 is configured to cool
discharge electrode 1 and generate condensation water as liquid 40
on the surface of discharge electrode 1. According to this
configuration, liquid supply unit 4 supplies liquid 40
(condensation water) to discharge electrode 1 using the moisture in
the air. This eliminates the need to provide another device for
supplying and replenishing the liquid to discharge device 10.
[0071] As shown in FIG. 3, voltage application unit 3 includes, for
example, an isolated AC/DC converter. Voltage application unit 3
converts AC power supplied from AC power supply AC via power cord
103 into DC power. Voltage application unit 3 then applies the
converted DC power between discharge electrode 1 and counter
electrode 2.
[0072] Specifically, voltage application unit 3 includes diode
bridge 31, isolation transformer 32, capacitor 33, resistors 34 and
35, a pair of input terminals 361 and 362, a pair of output
terminals 371 and 372, and the like.
[0073] Diode bridge 31 is, for example, an element in which four
diodes are connected in bridge. A pair of input ends of diode
bridge 31 is electrically connected to the pair of input terminals
361 and 362. A pair of output ends of diode bridge 31 is
electrically connected between both ends of primary winding 321 of
isolation transformer 32. Diode bridge 31 rectifies (for example,
provides full-wave rectification of) the AC power from AC power
supply AC input via the pair of input terminals 361 and 362.
[0074] Isolation transformer 32 includes primary winding 321 and
secondary winding 322. Primary winding 321 is electrically
insulated from and magnetically coupled to secondary winding 322.
One end of secondary winding 322 is electrically connected to, for
example, output terminal 371 of the pair of output terminals 371
and 372, and the other end of secondary winding 322 is electrically
connected to other output terminal 372 via resistor 35. Further,
smoothing capacitor 33 and resistor 34 are electrically connected
in parallel between both ends of secondary winding 322.
[0075] AC power supply AC is electrically connected between the
pair of input terminals 361 and 362 of voltage application unit 3.
Counter electrode 2 is electrically connected to, for example,
output terminal 371 of the pair of output terminals 371 and 372,
and discharge electrode 1 is electrically connected to other output
terminal 372.
[0076] Voltage application unit 3 applies a high voltage to
discharge electrode 1 and counter electrode 2. Here, the "high
voltage" indicates a voltage high enough to cause the
abovementioned partial breakdown discharge between discharge
electrode 1 and counter electrode 2. Specifically, voltage
application unit 3 applies a DC voltage of, for example, about -4
kV to discharge electrode 1 with counter electrode 2 grounded via
terminal piece 24. In other words, in a state where a high voltage
is applied from voltage application unit 3 to discharge electrode 1
and counter electrode 2, a potential difference with a side of
counter electrode 2 being high and a side of discharge electrode 1
being low is generated between discharge electrode 1 and counter
electrode 2.
[0077] Note that the value of the high voltage applied from voltage
application unit 3 to discharge electrode 1 and counter electrode 2
is set, as appropriate, depending on, for example, the shapes of
discharge electrode 1 and counter electrode 2, the distance between
discharge electrode 1 and counter electrode 2, etc.
[0078] According to voltage application unit 3 described above,
when the application voltage applied between output terminals 371
and 372 reaches a predetermined voltage (a voltage at which a
discharge starts), a discharge occurs between discharge electrode 1
and counter electrode 2. Along with the discharge, a relatively
large discharge current flows through voltage application unit 3.
At this time, the discharge current flows through resistors 34 and
35 of voltage application unit 3. Thus, the application voltage
applied between output terminals 371 and 372 becomes smaller than
the predetermined voltage, so that the discharge current is
interrupted. After that, the application voltage increases due to
the interruption of the discharge current, and reaches the
predetermined voltage again. When the application voltage reaches
the predetermined voltage, a discharge is generated between
discharge electrode 1 and counter electrode 2 again, and a
discharge current flows. Then, after that, the abovementioned
operation is repeated. Accordingly, a discharge occurs
intermittently.
(2.3) Shape of Protruding Electrode
[0079] Discharge device 10 according to the present exemplary
embodiment aims to increase the produced amount of acidic
components. To this end, discharge device 10 is configured such
that a partial breakdown discharge occurs between discharge
electrode 1 and protruding electrode 23 of counter electrode 2.
[0080] Further, in order to reduce the generated amount of ozone,
discharge device 10 needs to have a configuration for concentrating
an electric field on the tip of protruding electrode 23. In this
case, protruding electrode 23 preferably has a triangular shape as
shown in FIG. 5. In other words, the shape of protruding electrode
23 when viewed in the first direction (front-rear direction) is
preferably a triangle. The term "triangle" or "triangular shape"
described in the present disclosure is not limited to a so-called
common triangle having three vertices. For example, a shape in
which the tip is rounded as in protruding electrode 23 shown in
FIG. 5 is also included.
[0081] Further, it is preferable that, in order to concentrate the
electric field on tip 230 of protruding electrode 23 formed in a
triangular shape, the angle (vertex angle .theta.1) of tip 230 of
protruding electrode 23 is an acute angle. Meanwhile, protruding
electrode 23 is formed (molded) by a punching die as described
above. During formation, if the angle of tip 230 of protruding
electrode 23 is too small, there is a high possibility that the
punching die will be damaged. In view of this, it is preferable
that, in order to concentrate the electric field on tip 230 of
protruding electrode 23 while preventing damage of the punching
die, the angle of tip 230 of protruding electrode 23 is, for
example, 60 degrees or more. That is, as shown in FIG. 5, vertex
angle .theta.1 of the triangle is preferably 60 degrees or more.
Further, vertex angle .theta.1 of the triangle is more preferably
90 degrees.
[0082] Note that the shape of the triangle is preferably an
isosceles triangle including an equilateral triangle. In this case,
if the length of base 231 of the triangle is L1, and the length of
perpendicular line 233 from vertex 232 facing base 231 to base 231
is L2, Equation (1) is established.
[ Equation .times. .times. 1 ] .times. L .times. .times. 1 .gtoreq.
2 3 .times. L .times. .times. 2 ( 1 ) ##EQU00001##
[0083] From Equation (1), when vertex angle .theta.1 of the
triangle is 60 degrees or more, length L1 of base 231 is longer
than length L2 of perpendicular line 233. That is, base 231 of the
triangle is longer than perpendicular line 233 from vertex 232
facing base 231 to base 231. In this case, it is further preferable
that length L2 of perpendicular line 233 of the triangle is less
than or equal to a half of radius r1 of opening 222, as shown in
FIG. 5. When protruding electrode 23 is formed to have the
abovementioned triangular shape, the electric field can be
concentrated on tip 230 of protruding electrode 23 while preventing
damage to the punching die. As a result, a partial breakdown
discharge between discharge electrode 1 and protruding electrode 23
can be stably generated.
[0084] Note that, in the present exemplary embodiment, length L1 of
base 231 of the triangle of protruding electrode 23 is, for
example, 1 mm or less.
[0085] On the other hand, when tip 230 of protruding electrode 23
is sharp, the electric field is likely to concentrate on tip 230.
Therefore, electrolytic corrosion is likely to occur at tip 230 of
protruding electrode 23 due to the electric field. As a result, the
discharge state in the partial breakdown discharge between
discharge electrode 1 and protruding electrode 23 may change over
time due to shape variation by electrolytic corrosion. Therefore,
it is more preferable that tip 230 of protruding electrode 23 has a
curved surface such that the discharge state does not change over
time.
[0086] In view of this, as shown in FIGS. 4B and 5, each of the
pair of protruding electrodes 23 of the present exemplary
embodiment includes first curved surface 230a formed on a tip
surface (left end surface or right end surface) of tip 230 and
second curved surface 230b formed on the lower surface of tip 230
facing discharge electrode 1. That is, the surface facing discharge
electrode 1 at tip 230 of each of protruding electrodes 23 has a
curved surface. In the present exemplary embodiment, first curved
surface 230a and second curved surface 230b are formed to have a
radius of curvature of, for example, about 0.1 mm.
[0087] With this configuration, the electric field is concentrated
on the curved surfaces (first curved surface 230a and second curved
surface 230b) formed on tips 230 of protruding electrodes 23.
Therefore, the occurrence of electrolytic corrosion can be
suppressed as compared with the configuration where tips 230 of
protruding electrodes 23 are sharp. As a result, the occurrence of
a change over time in the discharge state due to the shape
variation of tips 230 of protruding electrodes 23 is suppressed.
Consequently, the discharge state of discharge device 10 can be
stably maintained for a long period of time.
(2.4) Partial Breakdown Discharge
[0088] Hereinafter, the partial breakdown discharge generated when
the application voltage is applied between discharge electrode 1
and counter electrode 2 will be described with reference to FIGS.
6A and 6B.
[0089] FIG. 6A is a conceptual diagram for describing the partial
breakdown discharge when liquid 40 is retained on discharge
electrode 1. FIG. 6B is a conceptual diagram for describing the
partial breakdown discharge when liquid 40 is not retained on
discharge electrode 1. Note that, in the description with reference
to FIG. 6A and the description with reference to FIG. 6B, "liquid
40 retained on discharge electrode 1" may be replaced by "tip 11 of
discharge electrode 1". Therefore, in the following, only FIG. 6A
will be described, and the description of FIG. 6B will be
omitted.
[0090] Discharge device 10 according to the present exemplary
embodiment first causes a local corona discharge in liquid 40
retained on discharge electrode 1. Since discharge electrode 1 of
the present exemplary embodiment is on the negative electrode side,
the corona discharge generated in liquid 40 retained on discharge
electrode 1 is a negative corona discharge.
[0091] Then, discharge device 10 develops the corona discharge
generated in liquid 40 retained on discharge electrode 1 to a
higher energy discharge. Due to the discharge with higher energy,
discharge path 200 in which the partial dielectric breakdown occurs
is formed between discharge electrode 1 and counter electrode
2.
[0092] At this time, the partial breakdown discharge is accompanied
by partial dielectric breakdown between discharge electrode 1 and
counter electrode 2, but dielectric breakdown is not continuously
generated. That is, the partial breakdown discharge is a discharge
in which the dielectric breakdown occurs intermittently. Therefore,
the flow of the discharge current generated between discharge
electrode 1 and counter electrode 2 also occurs intermittently.
That is, in a case where the power supply (voltage application unit
3) does not have a current capacity required to maintain discharge
path 200, the voltage applied between discharge electrode 1 and
counter electrode 2 reduces as soon as the corona discharge
develops to the partial breakdown discharge. As a result, discharge
path 200 formed between discharge electrode 1 and counter electrode
2 is interrupted, and the discharge is stopped. Note that the
"current capacity" indicates a capacity of current that can be
released in a unit time.
[0093] Then, the discharge current flows intermittently between
discharge electrode 1 and counter electrode 2 due to the repetition
of generation and stop of the discharge as described above. As
described above, in the partial breakdown discharge, a state having
high discharge energy and a state having low discharge energy are
repeated, and in that point, the partial breakdown discharge is
different from a glow discharge and an arc discharge in which
dielectric breakdown occurs continuously (that is, a discharge
current is continuously generated).
[0094] More specifically, voltage application unit 3 first applies
an application voltage between discharge electrode 1 and counter
electrodes 2 which face each other with a gap therebetween.
Accordingly, a discharge is generated between liquid 40 retained on
discharge electrode 1 and counter electrode 2. At this time, when
the discharge occurs, discharge path 200 in which dielectric
breakdown partially occurs is formed between discharge electrode 1
and counter electrode 2.
[0095] That is, discharge path 200 in which dielectric breakdown
occurs not entirely but partially (locally) is formed between
discharge electrode 1 and counter electrode 2. Thus, in the partial
breakdown discharge, discharge path 200 formed between discharge
electrode 1 and counter electrode 2 does not reach entire
dielectric breakdown, but has partial dielectric breakdown.
[0096] Here, discharge path 200 includes first dielectric breakdown
region 201 generated around discharge electrode 1 and second
dielectric breakdown region 202 generated around counter electrode
2 as described above. First dielectric breakdown region 201 is a
region where dielectric breakdown occurs around discharge electrode
1. Second dielectric breakdown region 202 is a region where
dielectric breakdown occurs around counter electrode 2.
[0097] At this time, discharge electrode 1 retains liquid 40 as
shown in FIG. 6A. Therefore, when the application voltage is
applied between liquid 40 and counter electrode 2, first dielectric
breakdown region 201 is generated particularly near the tip of
liquid 40 in a region around discharge electrode 1.
[0098] First dielectric breakdown region 201 and second dielectric
breakdown region 202 are generated apart from each other in
discharge path 200 so as not to come into contact with each other.
Therefore, discharge path 200 includes a region (insulation region)
where dielectric breakdown does not occur at least between first
dielectric breakdown region 201 and second dielectric breakdown
region 202. Accordingly, in the partial breakdown discharge, the
space between liquid 40 retained on discharge electrode 1 and
counter electrode 2 does not reach entire dielectric breakdown, but
has only partial dielectric breakdown, and the discharge current
flows through the space via discharge path 200. That is, when
discharge path 200 in which partial dielectric breakdown occurs, in
other words, discharge path 200 partially including a region where
dielectric breakdown does not occur, is used, a discharge current
flows between discharge electrode 1 and counter electrode 2 through
discharge path 200, and a discharge occurs.
[0099] In this case, second dielectric breakdown region 202 is
basically generated around the portion of counter electrode 2 where
the distance (spatial distance) to discharge electrode 1 is the
shortest. In discharge device 10 according to the present exemplary
embodiment, angle .theta.2 between central axis P1 of discharge
electrode 1 and the protrusion direction (X-axis direction) of
protruding electrode 23 is 90 degrees as shown in FIG. 6A.
Therefore, distance D3 (see FIG. 6A) between second curved surface
230b of tip 230 of protruding electrode 23 of counter electrode 2
and tip 40a (vertex) of the Taylor cone of liquid 40 formed on
discharge electrode 1 is the shortest. That is, second dielectric
breakdown region 202 is generated in the vicinity of the periphery
of second curved surface 230b of tip 230 of protruding electrode
23.
[0100] Here, counter electrode 2 of the present exemplary
embodiment has a plurality of (for example, two) protruding
electrodes 23 as described above. Protruding electrodes 23 are
disposed such that distance D3 from each protruding electrode 23 to
discharge electrode 1 is the same. Therefore, second dielectric
breakdown region 202 is generated in the vicinity of the periphery
of second curved surface 230b of tip 230 of any one of protruding
electrodes 23 among the plurality of protruding electrodes 23. That
is, protruding electrode 23 on which second dielectric breakdown
region 202 is generated is not limited to specific protruding
electrode 23, and is randomly determined among the plurality of
protruding electrodes 23 due to various factors in the event of a
discharge.
[0101] In other words, in the partial breakdown discharge, first
dielectric breakdown region 201 is generated in the vicinity of the
periphery of discharge electrode 1 so as to extend from discharge
electrode 1 toward counter electrode 2 which is a counterpart as
shown in FIG. 6A. On the other hand, second dielectric breakdown
region 202 is generated in the vicinity of the periphery of counter
electrode 2 so as to extend from counter electrode 2 toward
discharge electrode 1 which is a counterpart. With this
configuration, first dielectric breakdown region 201 and second
dielectric breakdown region 202 are generated so as to respectively
extend from discharge electrode 1 and counter electrode 2 in a
direction in which they attract each other. Therefore, each of
first dielectric breakdown region 201 and second dielectric
breakdown region 202 is generated in the direction along discharge
path 200 with a predetermined length according to the strength of
the electric field generated by the application voltage.
[0102] As described above, in the partial breakdown discharge, the
region where dielectric breakdown partially occurs (first
dielectric breakdown region 201 and second dielectric breakdown
region 202) is generated to have a shape extending in a specific
direction along discharge path 200.
[0103] Further, in the abovementioned partial breakdown discharge,
a large amount of energy is generated as compared with the corona
discharge. Due to the large amount of energy, oxygen and nitrogen
in the air chemically react with each other, for example, to
generate an acidic component such as nitrogen oxide. When attached
to, for example, skin, the generated acidic component makes the
skin mildly acidic. Therefore, the acidic component accelerates, in
the skin, the production of moisturizing ingredients such as
natural moisturizing molecules and intercellular lipids. In other
words, the acidic component has an effect of boosting the ability
of the skin to retain moisture. In addition, the acidic component
tightens cuticle that covers the surface of the hair. That is, the
acidic component also has an effect of preventing discharge of
water, nutrients, and the like from inside of the hair.
[0104] In addition, when acidic components are generated by the
partial breakdown discharge, ozone is also generated
simultaneously. Meanwhile, discharge device 10 according to the
present exemplary embodiment is configured such that an electric
field is concentrated on tip 230 of protruding electrode 23.
Accordingly, the generated amount of ozone can be suppressed to the
same extent as that in a corona discharge.
[0105] Further, in the partial breakdown discharge, large amounts
of radicals about 2 to 10 times as much as that in the corona
discharge are generated. The generated radicals are the basis for
providing useful effects in various situations, besides
sterilization, deodorization, moisture retention, freshness
retention, and inactivation of viruses. Therefore, the generated
radicals can also be effectively utilized.
(3) Product
[0106] Hereinafter, a product produced by discharge device 10
according to the present exemplary embodiment will be described
with reference to FIGS. 7A, 7B, and 8.
[0107] FIG. 7A is a graph showing a relationship among the
magnitude of the discharge current flowing between discharge
electrode 1 and counter electrode 2, presence or absence of
protruding electrode 23, and a ratio of a produced amount of acidic
components. FIG. 7B is a graph showing a relationship among the
magnitude of the discharge current flowing between discharge
electrode 1 and counter electrode 2, presence or absence of
protruding electrode 23, and a ratio of a generated amount of
ozone. FIG. 8 is a graph showing a relationship between presence or
absence of protruding electrode 23 and a ratio of a produced amount
of charged fine particle water.
(3.1) Produced Amount of Acidic Components
[0108] First, the produced amount of acidic components by the
discharge generated between discharge electrode 1 and counter
electrode 2 will be described with reference to FIG. 7A.
[0109] In FIG. 7A, a corona discharge in which a discharge current
is smaller than that in a partial breakdown discharge is indicated
as a comparison target for the produced amount of acidic
components.
[0110] That is, in FIG. 7A, the case in which the discharge current
is small corresponds to a corona discharge, and the case in which
the discharge current is large corresponds to a partial breakdown
discharge. Further, in FIG. 7A, the produced amount of acidic
components in a case where the corona discharge occurs without
providing protruding electrode 23 to counter electrode 2 is set as
a reference value (1.0), and produced amounts of acidic components
are expressed in a ratio to the reference value.
[0111] It can be seen from FIG. 7A that, in the case where the
corona discharge occurs and counter electrode 2 is provided with
protruding electrode 23, discharge device 10 produces an acidic
component in an amount 1.2 times the reference value. Similarly, it
can be seen that, in the case where the partial breakdown discharge
occurs and counter electrode 2 is not provided with protruding
electrode 23, discharge device 10 produces an acidic component in
an amount 1.2 times the reference value. On the other hand, it can
be seen that, in the case where the partial breakdown discharge
occurs and counter electrode 2 is provided with protruding
electrode 23, discharge device 10 produces an acidic component in
an amount 1.6 times the reference value.
[0112] That is, due to the configuration in which the partial
breakdown discharge is generated between discharge electrode 1 and
counter electrode 2, and protruding electrode 23 is provided on
counter electrode 2, discharge device 10 according to the present
exemplary embodiment can significantly increase the produced amount
of acidic components.
(3.2) Generated Amount of Ozone
[0113] Next, the generated amount of ozone generated by the
discharge caused between discharge electrode 1 and counter
electrode 2 will be described with reference to FIG. 7B.
[0114] Similar to FIG. 7A, in FIG. 7B, a corona discharge in which
a discharge current is smaller than that in partial breakdown
discharge is indicated as a comparison target for the generated
amount of ozone.
[0115] That is, in FIG. 7B, the case in which the discharge current
is small corresponds to a corona discharge, and the case in which
the discharge current is large corresponds to a partial breakdown
discharge. Further, in FIG. 7B, the generated amount of ozone in a
case where the corona discharge occurs without providing protruding
electrode 23 to counter electrode 2 is set as a reference value
(1.0), and generated amounts of ozone are expressed in a ratio to
the reference value.
[0116] It can be seen from FIG. 7B that, in the case where the
corona discharge occurs and counter electrode 2 is provided with
protruding electrode 23, discharge device 10 generates ozone in an
amount 0.7 times the reference value. On the other hand, it can be
seen that, in the case where the partial breakdown discharge occurs
and counter electrode 2 is not provided with protruding electrode
23, discharge device 10 generates ozone in an amount 1.2 times the
reference value. Further, it can be seen that, in the case where
the partial breakdown discharge occurs and counter electrode 2 is
provided with protruding electrode 23, discharge device 10
generates ozone in an amount 0.9 times the reference value.
[0117] That is, it can be found that, in discharge device 10 in
which protruding electrode 23 is provided on counter electrode 2,
the generated amount of ozone decreases in both the corona
discharge and the partial breakdown discharge.
[0118] Here, the reason why the generated amount of ozone decreases
is presumed as follows. First, the reaction between ozone and
nitrogen or nitrogen oxides proceeds due to the discharge between
discharge electrode 1 and counter electrode 2 (protruding electrode
23). Accordingly, ozone disappears, and it is estimated that the
generated amount of ozone will decrease.
[0119] Further, as shown in FIG. 7B, in discharge device 10 in
which protruding electrode 23 is provided on counter electrode 2,
the reduction in an amount of ozone is slightly greater in the
corona discharge than in the partial breakdown discharge. However,
the produced amount of acidic components is larger in the partial
breakdown discharge than in the corona discharge as shown in FIG.
7A.
[0120] It can be found from the above results that, considering
both amounts, the configuration in which the partial breakdown
discharge is caused, and protruding electrode 23 is provided on
counter electrode 2 is the most preferable. That is, due to the
configuration in which the partial breakdown discharge is generated
between discharge electrode 1 and counter electrode 2, and
protruding electrode 23 is provided on counter electrode 2,
discharge device 10 can reduce the generated amount of ozone, while
increasing the produced amount of acidic components.
(3.3) Produced Amount of Charged Fine Particle Water
[0121] Next, the produced amount of charged fine particle water by
the partial breakdown discharge caused between discharge electrode
1 and counter electrode 2 will be described with reference to FIG.
8.
[0122] In FIG. 8, the produced amount of charged fine particle
water in discharge device 10 in the case where counter electrode 2
is not provided with protruding electrode 23 is set as a reference
value (1.0), and a produced amount of charged fine particle water
is expressed in a ratio to the reference value.
[0123] It can be seen from FIG. 8 that, when protruding electrode
23 is provided on counter electrode 2 and the partial breakdown
discharge is generated between liquid 40 retained on discharge
electrode 1 and protruding electrode 23, charged fine particle
water in an amount 5 times the reference value is produced. That
is, it can be found that, due to the formation of protruding
electrode 23 on counter electrode 2, the produced amount of charged
fine particle water can be significantly increased as compared with
the configuration having no protruding electrode 23.
(4) Modifications
[0124] The exemplary embodiment is only one of various exemplary
embodiments of the present disclosure. The exemplary embodiment
described above can be variously modified according to the design
and the like as long as the object of the present disclosure can be
achieved. Modifications of the abovementioned exemplary embodiment
will be described below. Further, the modifications described below
can be applied in combination as appropriate.
(4.1) First Modification
[0125] In the abovementioned exemplary embodiment, angle .theta.2
between central axis P1 of discharge electrode 1 and the protrusion
direction of protruding electrode 23 is 90 degrees as shown in FIG.
6A as one example. However, the present disclosure is not limited
thereto. For example, angle .theta.2 between central axis P1 of
discharge electrode 1 and the direction in which protruding
electrode 23 protrudes may be an acute angle as shown in FIG. 9.
That is, protruding electrode 23 of counter electrode 2 may be
inclined in the first direction (front-rear direction: Y-axis
direction), that is, in a direction away from discharge electrode
1, with nearness to the center of opening 222. In this case, it is
necessary to set the shape, dimensions, and the like of inclined
protruding electrode 23 such that the distance between discharge
electrode 1 and tip 230 of protruding electrode 23 is the shortest.
With this configuration, the direction of force acting on discharge
electrode 1 and liquid 40 can be controlled by adjusting
inclination angle .theta.2 of protruding electrode 23. Further, the
location where the electric field is concentrated in protruding
electrode 23 can be adjusted. That is, when angle .theta.2 is
changed, the distance between protruding electrode 23 and discharge
electrode 1 changes, so that the state of occurrence of discharge
changes. Therefore, the direction of force acting on discharge
electrode 1 and liquid 40 can be controlled.
(4.2) Second to Fifth Modifications
[0126] In the abovementioned exemplary embodiment, a plurality of
protruding electrodes 23 is arranged so as to face each other in
the lateral direction (X-axis direction) as shown in FIG. 4A as one
example. However, the present disclosure is not limited thereto.
For example, as in the second modification shown in FIG. 10A, a
plurality of protruding electrodes 23A of counter electrode 2A may
be arranged so as to face each other in the vertical direction
(Z-axis direction).
[0127] Further, in the abovementioned exemplary embodiment and the
second modification, a number of protruding electrodes 23 and 23A
is two as an example, but the present disclosure is not limited
thereto. For example, as in the third modification shown in FIG.
10B or the fourth modification shown in FIG. 10C, a number of
protruding electrodes 23B and 23C may be four. With the
configurations of the modifications, the life of the protruding
electrode can be extended.
[0128] In FIGS. 10B and 10C, the rightward direction corresponds to
the direction of 0 degrees, and the leftward direction corresponds
to the direction of 180 degrees.
[0129] That is, in the third modification, four protruding
electrodes 23B are positioned at 45 degrees, 135 degrees, 225
degrees, and 315 degrees when counter electrode 2B is viewed from
front (Y-axis direction), as shown in FIG. 10B.
[0130] Further, in the fourth modification, four protruding
electrodes 23C are positioned at 0 degrees, 90 degrees, 180
degrees, and 270 degrees when counter electrode 2C is viewed from
front, as shown in FIG. 10C.
[0131] Further, in the abovementioned exemplary embodiment and the
second to fourth modifications, protruding electrodes 23 and 23A to
23C are formed integrally with electrode bodies 21 of counter
electrodes 2 and 2A to 2C, but the present disclosure is not
limited thereto. For example, as shown in the fifth modification
shown in FIG. 10D, protruding electrodes 23D may be provided
separately from electrode body 21 of counter electrode 2D. In this
case, protruding electrodes 23D are fixed to electrode body 21 by
an appropriate fixing method (for example, screw fixation,
caulking, etc.).
[0132] According to the second to fifth modifications, protruding
electrodes 23A to 23D are provided on counter electrodes 2A to 2D,
and a partial breakdown discharge is generated between discharge
electrode 1 and protruding electrodes 23A to 23D. Thus, similar to
discharge device 10 in the above exemplary embodiment, the
generated amount of ozone can be reduced while increasing the
produced amount of acidic components.
[0133] Hair care device 100 equipped with discharge device 10 using
counter electrode 2 according to the above exemplary embodiment and
hair care device 100A equipped with discharge device 10A using
counter electrode 2A according to the second exemplary embodiment
will be described below with reference to FIGS. 2B and 11.
[0134] FIG. 2B is a perspective view showing that discharge device
10 using counter electrode 2 according to the above exemplary
embodiment is incorporated into hair care device 100. FIG. 11 is a
perspective view showing that discharge device 10A using counter
electrode 2A according to the second modification is incorporated
into hair care device 100A.
[0135] Note that flow path 300 shown in FIGS. 2B and 11 indicates
the flow of air from airflow generator 20 to discharge devices 10
and 10A. Lower arrows AA and BB shown in FIGS. 2A and 11 indicate
flow paths of hot air or cold air discharged from hair care devices
100 and 100A.
[0136] In FIG. 11, upper protruding electrode 23A of two protruding
electrodes 23A arranged in the vertical direction is located at a
position where the velocity of airflow is relatively low, and lower
protruding electrode 23A is located at a position where the
velocity of airflow is relatively high. In this configuration, when
a discharge is generated between discharge electrode 1 and counter
electrode 2A, the frequency of discharge generated by lower
protruding electrode 23A increases, because it is considered that,
for example, the higher the flow velocity, the more quickly air
which is the material of the discharge reaction is replaced. That
is, the frequency of discharge differs between upper protruding
electrode 23A and lower protruding electrode 23A. As a result,
there is a difference in electrolytic corrosion between them.
[0137] On the other hand, in FIG. 2B, two protruding electrodes 23
arranged in the lateral direction are located at positions where
the airflow flows at substantially the same velocity (including the
same velocity). Therefore, when a discharge is generated between
discharge electrode 1 and counter electrode 2, the discharge is
generated substantially uniformly (including uniformly) on two
protruding electrodes 23. That is, the frequency of discharge is
substantially the same (including the same) between two protruding
electrodes 23. As a result, a difference in wear (difference in
electrolytic corrosion) is unlikely to occur between them.
[0138] For the above reasons, it is preferable that the plurality
of protruding electrodes 23 is arranged in flow path 300 of airflow
generated by airflow generator 20 and at positions where the
airflow flows at substantially the same velocity.
(4.3) Other Modifications
[0139] The mode of discharge adopted by discharge device 10 is not
limited to the mode described in the exemplary embodiment described
above. For example, discharge device 10 may employ a discharge in a
mode in which a phenomenon where dielectric breakdown occurs due to
development of a corona discharge is intermittently repeated, that
is, discharge device 10 may employ an "entire breakdown discharge".
In this case, when dielectric breakdown occurs due to development
of a corona discharge, a relatively large discharge current
momentarily flows through discharge device 10. As a result,
immediately after that, the application voltage drops, and the
discharge current is interrupted. Thereafter, the application
voltage rises again, and dielectric breakdown occurs. Such
phenomenon is repeated.
[0140] Further, the number of protruding electrodes 23 is not
limited to two or four, and may be, for example, one, three, or
five or more. This can extend the life of electrodes.
[0141] Further, in the exemplary embodiment and modifications
mentioned above, a plurality of protruding electrodes 23 is
arranged at equal intervals in the circumferential direction of
opening 222 as an example, but the configuration in which the
plurality of protruding electrodes 23 is arranged at equal
intervals is not necessary. For example, a plurality of protruding
electrodes 23 may be arranged at arbitrary intervals in the
circumferential direction of opening 222.
[0142] Further, discharge device 10 may not include liquid supply
unit 4 that generates charged fine particle water. In this case,
discharge device 10 generates air ions by the partial breakdown
discharge generated between discharge electrode 1 and counter
electrode 2. Accordingly, when mounted on, for example, a dryer,
discharge device 10 can increase an effect of managing hair due to
generation of negative ions in addition to acidic components.
[0143] In addition, in comparison between two values such as a
threshold and a target value, the wording "greater than or equal
to" includes both a case where the two values are equal to each
other and a case where one of the two values exceeds the other.
However, the present disclosure is not limited thereto, and the
wording "greater than or equal to" herein may have the same meaning
as the wording "greater than" which includes only a case where one
of the two values exceeds the other. In other words, whether the
wording "greater than or equal to" includes the case where the two
values are equal to each other can be arbitrarily changed depending
on setting of a threshold or the like. Therefore, there is no
technical difference between the wording "greater than or equal to"
and the wording "greater than". Similarly, the wording "less than"
may have the same meaning as the wording "less than or equal
to".
SUMMARY
[0144] As described above, discharge device (10; 10A) according to
one aspect of the present disclosure includes discharge electrode
(1), counter electrode (2; 2A to 2D), and voltage application unit
(3). Counter electrode (2; 2A to 2D) faces discharge electrode (1)
in a first direction (for example, the front-rear direction).
Voltage application unit (3) generates a discharge by applying an
application voltage between discharge electrode (1) and counter
electrode (2; 2A to 2D). Counter electrode (2; 2A to 2D) includes
dome-shaped electrode (22) and protruding electrode (23; 23A to
23D). Dome-shaped electrode (22) has recessed inner surface (221)
recessed to a side opposite to discharge electrode (1) in the first
direction. Protruding electrode (23; 23A to 23D) protrudes in a
second direction (for example, lateral direction) intersecting the
first direction from opening edge (222a) of opening (222) of
dome-shaped electrode (22), opening (222) being provided at an end
opposite to discharge electrode (1). Discharge device (10) forms
discharge path (200) that has at least partial dielectric breakdown
between discharge electrode (1) and protruding electrode (23; 23A
to 23D) when the discharge occurs. Discharge path (200) includes
first dielectric breakdown region (201) and second dielectric
breakdown region (202). First dielectric breakdown region (201) is
generated around discharge electrode (1). Second dielectric
breakdown region (202) is generated around protruding electrode
(23; 23A to 23D).
[0145] According to this aspect, discharge path (200) including
first dielectric breakdown region (201) and second dielectric
breakdown region (202) is formed between discharge electrode (1)
and protruding electrode (23; 23A to 23D). With this configuration,
the produced amount of acidic components can be increased as
compared with the case of the corona discharge. In addition, an
electric field can be concentrated on a tip of protruding electrode
(23; 23A to 23D). Accordingly, the generated amount of ozone can be
suppressed to the same extent as that in the corona discharge.
[0146] Further, in discharge device (10; 10A) according to one
aspect of the present disclosure, counter electrode (2; 2A to 2D)
includes a plurality of protruding electrodes (23; 23A to 23D). The
plurality of protruding electrodes (23; 23A to 23D) is arranged at
equal intervals along the circumferential direction of opening
(222).
[0147] According to this aspect, in a case where a Taylor cone is
formed at tip (11) of discharge electrode (1), a variation in shape
of the Taylor cone can be reduced. As a result, a dielectric
breakdown state of protruding electrodes (23; 23A to 23D) can be
stabilized.
[0148] Further, in discharge device (10; 10A) according to one
aspect of the present disclosure, the plurality of protruding
electrodes (23; 23A; 23D) is a pair of protruding electrodes (23;
23A; 23D).
[0149] According to this aspect, an electric field can be
concentrated on protruding electrodes (23; 23A; 23D). As a result,
the discharge between discharge electrode (1) and protruding
electrode (23; 23A; 23D) can be stabilized.
[0150] Further, in discharge device (10; 10A) according to one
aspect of the present disclosure, the shape of protruding electrode
(23; 23A to 23D) as viewed in the first direction is a
triangle.
[0151] According to this aspect, an electric field can be
concentrated on tip (230) of protruding electrode (23; 23A to 23D).
As a result, the discharge between discharge electrode (1) and
protruding electrode (23; 23A to 23D) can be stabilized.
[0152] Further, in discharge device (10; 10A) according to one
aspect of the present disclosure, vertex angle (01) of the triangle
is 60 degrees or more.
[0153] According to this aspect, when the shape of protruding
electrode (23; 23A to 23C) is punched by using, for example, a
punching die, damage of the die can be reduced as compared with a
configuration where vertex angle (01) is less than 60 degrees.
[0154] Further, in discharge device (10; 10A) according to one
aspect of the present disclosure, base (231) of the triangle which
is the shape of protruding electrode (23; 23A to 23D) is longer
than perpendicular line (233). Perpendicular line (233) is a
straight line from vertex (232) facing base (231) to base
(231).
[0155] According to this aspect, when the shape of protruding
electrode (23; 23A to 23C) is punched by using, for example, a
punching die, damage of the die can be reduced as compared with a
configuration where base (231) is shorter than perpendicular line
(233).
[0156] Further, in discharge device (10; 10A) according to one
aspect of the present disclosure, the shape of opening (222) as
viewed in the first direction is circular. Length (L2) of
perpendicular line (233) is less than or equal to a half of radius
(r1) of opening (222).
[0157] According to this aspect, when the shape of protruding
electrode (23; 23A to 23C) is punched by using, for example, a
punching die, damage of the die can be reduced as compared with a
configuration where length (L2) of perpendicular line (233) is
longer than a half of radius (r1) of opening (222).
[0158] Further, in discharge device (10; 10A) according to one
aspect of the present disclosure, the triangle which is the shape
of protruding electrode (23; 23A to 23D) as viewed in the first
direction is isosceles triangle.
[0159] According to this aspect, in a case where a Taylor cone is
formed at tip (11) of discharge electrode (1), an occurrence of a
variation in shape of the Taylor cone can be suppressed without
fine adjustment. As a result, a stable discharge can be obtained
between discharge electrode (1) and protruding electrode (23; 23A
to 23D).
[0160] Further, in discharge device (10; 10A) according to one
aspect of the present disclosure, first dielectric breakdown region
(201) and second dielectric breakdown region (202) are formed apart
from each other in discharge path (200).
[0161] According to this aspect, a discharge current can be reduced
as compared with a case where dielectric breakdown is caused in
entire discharge path (200). As a result, wear of protruding
electrode (23; 23A to 23D) due to electrolytic corrosion can be
reduced.
[0162] Further, in discharge device (10; 10A) according to one
aspect of the present disclosure, protruding electrode (23; 23A to
23D) may be inclined in a direction away from discharge electrode
(1) in the first direction.
[0163] According to this aspect, a direction of force acting on
discharge electrode (1) and liquid (40) retained on discharge
electrode (1) can be controlled by adjusting inclination angle (02)
of protruding electrode (23; 23A to 23D). In addition, the location
where the electric field is concentrated on protruding electrode
(23; 23A to 23D) can be adjusted.
[0164] Further, in discharge device (10; 10A) according to one
aspect of the present disclosure, a surface facing discharge
electrode (1) at tip (230) of protruding electrode (23; 23A to 23D)
includes a curved surface.
[0165] According to this aspect, tip (230) of protruding electrode
(23; 23A to 23D) where an electric field is concentrated has a
curved surface, whereby wear due to electrolytic corrosion can be
reduced. As a result, a desired discharge state can be maintained
for a long period of time.
[0166] Further, in discharge device (10; 10A) according to one
aspect of the present disclosure, counter electrode (2; 2A)
includes a plurality of protruding electrodes (23; 23A). The
plurality of protruding electrodes (23; 23A) is arranged in flow
path (300) of an airflow generated by airflow generator (20) and at
positions where the airflow flows at the same velocity.
[0167] According to this aspect, imbalance of electrolytic
corrosion caused between the plurality of protruding electrodes
(23; 23A) can be reduced.
[0168] In addition, hair care device (100; 100A) according to one
aspect of the present disclosure includes discharge device (10;
10A) according to the above aspect and airflow generator (20).
Airflow generator (20) generates an airflow with respect to
discharge device (10; 10A).
[0169] According to this aspect, hair care device (100; 100A)
capable of increasing a produced amount of acidic components can be
achieved using discharge device (10; 10A) described above.
[0170] It should be noted that all of the configurations described
in each aspect of discharge device (10; 10A) are not necessary for
discharge device (10; 10A) and can be eliminated as
appropriate.
INDUSTRIAL APPLICABILITY
[0171] The discharge device according to the present disclosure can
be applied to various applications such as refrigerators, washing
machines, hair care devices such as hair dryers, air conditioners,
electric fans, air purifiers, humidifiers, facial equipment, and
automobiles.
REFERENCE MARKS IN THE DRAWINGS
[0172] 1 discharge electrode [0173] 2, 2A, 2B, 2C, 2D counter
electrode [0174] 3 voltage application unit [0175] 4 liquid supply
unit [0176] 5 housing [0177] 10, 10A discharge device [0178] 11,
40a tip [0179] 12 base end [0180] 20 airflow generator [0181] 21
electrode body [0182] 22 dome-shaped electrode [0183] 23, 23A, 23B,
23C, 23D protruding electrode [0184] 24 terminal piece [0185] 31
diode bridge [0186] 32 isolation transformer [0187] 33 capacitor
[0188] 34, 35 resistor [0189] 40 liquid [0190] 41 cooling device
[0191] 51 caulking projection [0192] 100, 100A hair care device
[0193] 101 casing [0194] 102 grip [0195] 103 power cord [0196] 104
vent hole [0197] 200 discharge path [0198] 201 first dielectric
breakdown region [0199] 202 second dielectric breakdown region
[0200] 211 caulking hole [0201] 221 inner surface [0202] 221a first
edge [0203] 221b second edge [0204] 222 opening [0205] 222a opening
edge [0206] 230 tip [0207] 230a first curved surface [0208] 230b
second curved surface [0209] 231 base [0210] 232 vertex [0211] 233
perpendicular line [0212] 300 flow path [0213] 321 primary winding
[0214] 322 secondary winding [0215] 361, 362 input terminal [0216]
371, 372 output terminal [0217] 411 Peltier element [0218] 412
radiator plate [0219] 413 insulating plate [0220] r1 radius [0221]
.theta.1 vertex angle [0222] .theta.2 angle
* * * * *